An electric vehicle requires a power source having a large capacity and hence, an energy storage apparatus provided with a plurality of battery cells is used (see JP-A-2009-170258). As shown in FIG. 12, the energy storage apparatus of this type includes: a battery stack (not shown in the figure) formed by stacking a plurality of battery cells 33; a battery holder (not shown in the figure) which is disposed outside of the battery stack and fixes the stacked battery cells 33; and spacers 15 each of which is sandwiched between the stacked battery cells 33.
In the energy storage apparatus of this type, a cooling gap 50 through which cooling air flows in a direction orthogonal to a direction along which the battery cells 33 and the spacers 15 are arranged in a row is formed between the battery cells 33 and the spacer 15 arranged adjacently to the battery cells 33. Cooling air flows through the cooling gap 50 and cools the battery cells 33.
In the energy storage apparatus of this type, there may be a case where a gap is formed between the spacer 15 and another spacer 15 arranged adjacently to each other in a state where the battery cells 33 are assembled to each other.
Accordingly, in the energy storage apparatus of this type, a part of cooling air leaks to the outside through a gap 55 before cooling air contributes to the cooling of the battery cell 33 (before cooling air flows into the cooling gap 50) thus giving rise to a drawback that an effect of cooling the battery cell 33 is not improved.